Hayward SP0710XR50 Pro-Series Vari-Flo Backwash Valve Coupling Vertical grid D.E. filter replacement parts Hayward 6-position valve has an easy-to-use handle, heavy duty stainless steel spring ABS body and cover, neoprene valve seat, and a built-in sight glass; automatic self-cleaning design prevents clogging or sticking Vari-Flo valve assembly;1-1/2-inch NPT